Biochar has been known for many years as a soil enhancer. It contains highly porous, high carbon content material similar to the type of very dark, fertile anthropogenic soil found in the Amazon Basin known as Terra Preta, which has very high carbon content and historically has been made from a mixture of charcoal, bone, and manure. Biochar is created by the pyrolysis of biomass, which generally involves heating and/or burning of organic matter, in a reduced oxygen environment, at a predetermined rate. Such heating and/or burning is stopped when the matter reaches a charcoal like stage. The highly porous material of biochar is suited to host beneficial microbes, retain nutrients, hold water, and act as a delivery system for a range of beneficial compounds and additives suited to specific applications.
Raw biochar, while known for its soil enhancing characteristics, does not always benefit soil and, depending upon the biomass from which the biochar is produced and the method of production, can potentially be harmful to the soil, making it unsuitable for various types of crops or other productive uses. Biochars derived from different biomass or produced with differing parameters, such as higher or lower pyrolysis temperature or variations in residence time, will have different physical and chemical properties and can behave quite differently when used in agriculture. For example, biochar having pH levels too high, containing too much ash, inorganics, or containing toxins or heavy metal content too high can be harmful and/or have minimal benefit to the soil and the plant life it supports. Biochar can also contain unacceptable levels of residual organic compounds such as acids, esters, ethers, ketones, alcohols, sugars, phenyls, alkanes, alkenes, phenols, polychlorinated biphenyls or poly or mono aromatic hydrocarbons which are either toxic or not beneficial to plant or animal life. Many characteristics of the biochar can be altered through treatment, including but not limited to pH adjustment, hydrophobicity adjustment, and the removal of contaminants. Treatment can thus provide a biochar that is more effective in its application. Thus, creating biochar at scale that has generally sustainable, controllable and/or physical and chemical properties and effectiveness in an intended application can be accomplished through specific biomass selection, pyrolysis method and conditions, and post pyrolysis treatment process.
As populations grow, concerns over trash management and limited landfill space increases. Recycling by means of composting is a method to combat these concerns and is thus expected to increase globally. It is estimated that by the year 2020, 50% of food residuals will need to be diverted away from landfills. Composting of food residuals is an option, but it is recognized that food composting attracts nuisance animals and produces strong odors and can often produce inferior compost products.
Composting, often described as natural recycling, is the biological process of breaking up organic waste into an extremely useful humus-like substance by various micro-organisms. At the simplest level, the process of composting simply requires making a pile of wetted organic matter or green waste, such as leaves and food waste, and waiting for the material to break down into humus after a period of weeks. For commercial composting methods, there are two generally recognized commercial composting methods. These composting methods include covered aerated static pile (“CASP”) composting and composting using windrows. In the CASP composting method, the composting material is generally aerated by a blower and a perforated aeration pipe inserted into the composting material. In windrow composting, the composting material is aerated by mechanical turnover.
The effectiveness of composting itself and the final compost product is controlled by several factors, such as oxygen, temperature, time, nutrients, moisture, pH levels and particles size. A need exists for a way to control these factors to create a better compost product while also reducing emissions, odors, and nuisance animal attractions during the composting process.